Liquids, such as syrups used in soft drinks, frequently are packaged in bags contained in boxes of corrugated paper from which they must be dispensed for fountain and bar use. Consequently, an arrangement must be provided to rapidly connect a probe to the box through which the liquid is to be dispensed, as controlled by a suitable valve member. A device of this type is shown in U.S. Pat. No. 4,445,551, which includes a spout attached to the bag and a valve member movable within the spout. Opening of the valve is accomplished by inserting the liquid-dispensing probe into the valve and pushing it inwardly to uncover openings through which the liquid can flow. In order to permit the valve to be closed, the design of this patent includes a plurality of small lugs, each on a thin resilient arm, which has an outwardly extended free position. These arms and the lugs must be deflected inwardly so as to enter a groove in the probe. These lugs are held in their deflected inward position by the wall of the spout as the valve member is moved axially into the spout. Hence, reverse axial movement of the probe can move the valve outwardly to close it. The arms then spring outwardly of their own accord to release the probe.
However, these individual lugs on the thin arms are relatively delicate and have some vulnerability to damage, when exposed. Moreover, in this design there is no positive stop to retain the valve in its closed position prior to entry of the probe into the valve. Only friction holds it in this position. Hence, the valve can be moved inadvertently to the opened position before the probe is inserted. In general, the ruggedness and reliability of prior art liquid dispensers need improvement, and excessive expense and complexity have been a problem.